Ecological speciation, a key driver of global biodiversity, occurs when new species arise through adaptation to different ecological niches. Despite its significance, the mechanisms behind this process are not yet fully understood. Adaptive radiations rapid bursts of speciation producing many diverse species in short evolutionary timescales offer valuable insights. Increasingly, genome sequencing highlights the role of hybridization and gene flow between species in generating the genetic diversity required for ecological speciation and adaptive radiation.

A central puzzle in this process is the role of meiotic recombination. While recombination can generate beneficial new allele combinations, it also disrupts co adapted gene complexes, potentially hindering speciation. Chromosomal inversions segments of DNA reversed in orientation may resolve this paradox. By suppressing recombination with the standard chromosomal arrangement, inversions can preserve adaptive allele combinations as supergenes. Although inversions have been shown to contribute to ecological adaptation and speciation in various organisms, their role in adaptive radiations remains underexplored.

To bridge this knowledge gap, we conducted a comprehensive investigation into chromosomal inversions within the Lake Malawi cichlid fish radiation, the largest recent vertebrate adaptive radiation.

Source: https://www.science.org/doi/10.1126/science.adr9961